Todd Selby's photographs are cool. It feels distinctly uncool to write this, and even more so to ask him about it, but that's what he's known for. That's what he does. He photographs interesting people in their interesting homes, and in doing so has coined a style of photography and portraiture much imitated. A style that has come to define "cool". The images on his website, theselby.com, provoke equal parts envy and inspiration – alongside various artists, pub landlords and chefs you'll stumble upon Karl Lagerfeld and Philippe Starck, Helena Christensen and Pharrell Williams – but the thread that runs through the whole archive is the thing that Selby brings. The personality.

Todd Selby is 33 and grew up where farmland meets suburbia: Orange County, California. His father, a neurologist, photographs sunsets as a hobby. The family travelled throughout his youth, and the house is filled with "mud men from Papua New Guinea, bits of dinosaur poop. The house isn't planned, or tasteful," he says. But it is tidy. It was in search of "mess and excitement" that he moved to New York, where he developed his photography, putting together a portfolio of his friends' homes in 2001 and launching his blog in 2008. He still shoots friends, and friends of friends, and, regardless of their fame or fortune, every shoot goes the same way. "I always go by myself, so it's never like a 'photo shoot', and I ask for a tour," he says. "I want to see what they're proud of."

Over the years, through the homes, I wonder what trends he's seen rise and fall. He thinks. "Taxidermy. I started to notice a lot of stuffed animals, then a lot of fake stuffed animals. Perhaps I was the last one to figure out it had been and gone, but now I don't shoot taxidermy – I try not to be a cliché."

How much of the process is them and how much him? "The main thing is that I choose the people I shoot. Sometimes their homes could be in a design magazine, but more often they're just real people's homes, rather than manicured spaces. Which I love. My mum says I've made a whole career out of saying: 'Being messy is cool.'"

So I ask Selby about being cool. About defining the word hipster. "Yeah, I'm excited if people think that; I embrace it. It's about a DIY ethos, a respect for artists."

His shoots continue to steal our afternoons as we click through his blog, salivating, from one room to the next.

What makes a beautiful home? "I think the best ones express their owners' creative personalities. They don't need to be rich, or follow trends, or tidy up. They just need to be themselves."